Fine tune sensor alignment

Hi all, im kindly asking for your help. Im sure this matter has been covered before but i fail to find a post with the information i need in a timely manner.
Can anyone please indicate what each screw under the Alpha A200 is used for?

I know for sure they are used to align the sensor but i cant figure out what screw does what. All my lenses are back focusing so i assume this is a sensor issue and not a lens issue.